Political parties have been warned not to send election leaflets that mimic local newspapers.
Industry group the Society of Editors said the practice could undermine trust in local publications.
Its executive director Ian Murray said the public would not forgive politicians who “attempt to take them for mugs”.
All major parties have been criticised for the tactic ahead of next week’s poll.
The Newsquest group, which publishes a number of local titles, has written to main party leaders calling on them to end the “extremely worrying” practice.
In an open letter, the group’s titles said: “Not only are you taking advantage of our highly trusted credentials, you are also actively undermining our business models”.
“Imitation may be the sincerest form of flattery, but this has to stop.”
Among recent examples, the Lib Dems have faced criticism for a leaflet they produced in support of their candidate in Winchester, entitled the “Mid Hampshire Gazette”.
The editor of the Hampshire-based Basingstoke Gazette said such party material could erode trust in local papers, and called for an apology.
BBC News has been contacted by a reader in Tunbridge Wells with an example of a similar Lib Dem leaflet, entitled “Tunbridge Wells Gazette”.
The Conservatives have also produced a series of leaflets with different names in the style of red-top tabloid newspapers.
Examples include the “Pudsey Future,” “Birmingham Northfield Future” and “Aberconwy Future”.
Another BBC News reader sent in a Conservative leaflet from the Worcester constituency, which appeared to imitate a lifestyle magazine.
A Labour leaflet produced to support its candidate in the London constituency of Tooting, with a dark blue masthead carrying the title “Daily Press”, has attracted criticism on social media.
Mr Murray said: “If a politician or their party can attempt to deliberately mislead you by cloaking their partisan messages in the disguise of an independent and trusted local newspaper, what else are they attempting to camouflage?
“If there is no wish to deceive, then why give the publication a similar title to the existing independent newspaper in the area, as is often the case.
“Should a reader simply mistake a political freesheet for a version of their regular paper or, worse, believe their local editor has sided with one party over another then the destruction of decades, in some cases over a century, of impartial, non-partisan reporting will be assured.
“It is time the practice was brought to an end, for the sake of local newspapers but also, I would contend, for the sake of local politics.
“The public are not fooled for long and will not forgive politicians who attempt to take them for mugs.”